The present invention relates generally to an electrical connector and, more specifically, to an electrical connector employing an insulator and sheetmetal contact strips of substantially rectangular cross-section which are tight-fittingly inserted into curved recesses in the insulator.
There is a need for the present invention especially in the case of multipoint connectors of standardized design, in which the sheetmetal contacts are arranged in accordance with the international modular contact spacing 1 M = 2.54 mm (0.100 in.). The invention, however, can also be applied to a contact supporting plate employing strip-shaped contact members, such as in the stator plate of a rotary multi-position switch.
As regards multipoint electrical connectors it is known to mount the contact members in the form of contact strips 0.1 mm thick and 1.1 mm wide on an insulator designed as an insulation comb. Such type of contact is bent by 180.degree. on its plug-in side, to form a U-shaped element. Mounting of the thus bent contact is effected in such a way that the contact is inserted with its non-bent end in a slot of the insulator until reaching a limit stop of its bent U-leg or U-base, and a short piece of the other U-leg projecting out of the slot is form-lockingly connected to the insulator. To this end, for example, nose members may be arranged, for example, along the longitudinal edges of the contacts. In this type of mounting, the U-leg or U-base of the contact applied to the insulator serves as the mounting support while the nose members arranged on the other U-leg serve to act as mounting abutments.
An insulator thus equipped with contacts, however, has several disadvantages. In cases where the contacts are inserted with a press fit into the slot-shaped recesses of the insulator, the latter is easily caused to become cracked, with these cracks likely to impair the mechanical stability of the insulator. If the contacts are inserted in a loosely fitting manner into the slot-shaped recesses, thin gaps result between the contacts and the recesses which is likely to transport the colophony used during the soldering of the connecting lugs owing to capillary effects. This results in an impairment of the electrical contact properties of the U-legs of the contacts which, as is well known, are coated with a contact material, such as gold, for the purpose of obtaining special contacting properties.
These disadvantages can be overcome by designing the recesses in which the contact strips are embedded, not in a slot-shaped manner, but circularly. In the conventional type of mounting the sheetmetal contact member is inserted in such a way into a cylindrical recess in the insulator that the sheetmetal cutting edges of the contact are pressed into the limiting wall of the recess. From this the advantage results that the sheetmetal contact member can be inserted with a press fit, hence safe against torsion and displacement, without causing the aforementioned capillary effects or cracks in the insulator. The known solution, however, is again disadvantageous in cases where the contact members in the form of contact strips are supposed to be inserted in a certain oriented manner in an insulator or any other supporting plate.
Furthermore, disadvantages will always result in cases where the individual contacts are to be arranged at a very small spaced relation, e.g. at a spaced relation of 1 M = 2.54 mm into the insulator in a manner safe against distortions and displacements. In these cases only little space is available for notching or cutting noses, or the like into the sheetmetal cutting edges with the aid of stable forces for the purpose of forming a mounting support for the contact.
It is the purpose of the present invention to provide a multipoint connector in which sheetmetal contacts are retained in the connector insulator in a torsion- and displacement- proof manner as well as in an oriented direction, without the aforementioned capillary effects or cracks appearing in the insulator.